98 



Mr. E. Scliunck on the Colouring and 



C,, 144 13-10 



19 1-72 



152 13-85 



7PbO 784 71-33 



1099 100-00 



The brown glutinous mass («) wliich was left undissolved by cold 

 alcohol was treated with cold water, and the liquid, after being filtered 

 from the insoluble matter (/), which consisted for the most part of chloride 

 of lead, v/as evaporated as usual by means of a current of air. During 

 evaporation some more chloride of lead was deposited, which was sepa- 

 rated, and there was left at last a thin syrup, which was poured into a 

 flask and agitated with alcohol. The alcohol converted it into a milky 

 emulsion, which, after standing some time, deposited a brown glutinous 

 substance, the supernatant liquid becoming clear. The latter having been 

 poured off, the deposit was dissolved in cold water, and to the solution 

 there was added acetate of lead and sufficient ammonia to cause a slightly 

 alkaline reaction. The precipitate {g) which was thereby produced was 

 filtered off, washed with v/ater, and, after being suspended in water, decom- 

 posed with sulphuretted hydrogen. The liquid filtered from the sulphide 

 of lead was evaporated in the air-current, when it left a brown syrup, 

 which was treated with alcohol. The alcoholic liquid, after being filtered 

 from some insoluble matter, consisting of crystals mixed with a little glu- 

 tinous substance, was evaporated as before to a syrup, and this syrup was 

 poured into a flask and agitated with successive portions of ether until 

 nothing more was dissolved. The ethereal solution (A) having been poured 

 off, the insoluble matter was treated with cold alcohol, which dissolved 

 almost the whole of it. To the filtered liquid there was added a little 

 alcoholic solution of acetate of lead ; and the precipitate thereby produced 

 having been filtered off, more lead solution was added, which gave a 

 copious precipitate (i) of a greyish cream-colour. This, after being filtered 

 off and treated in the same manner as the other lead precipitates, w^as 

 analyzed, the results obtained being as follows : — 



Y. 1-3455 grm. gave 0-8455 grm. carbonic acid and 0*2830 grm. water. 



1-5710 grm.. gave 0*2490 grm. chloride of platinum and ammonium. 



0- 8830 grm. gave 0*7065 grm. sulphate of lead. 



1- 4975 grm. gave 0*2580 grm. chloride of silver, equivalent to 0-2508 

 grm. chloride of lead. 



In 100 parts it was therefore composed as follows : — 



C 17-13 



H 2-33 



N 0-99 



O.... 17-38 



PbO 45-43 



PbCl 16-74 



100-00 



